VERIZON PAPER - 17 NOV 2006 - CHENNAI

1). Two trains are on the same track a distance 300 km apart heading towards
one another, One at a speed of 150 km/h and other at a speed of 50 km/h. A fly
starting out at the front of one train, flies towards the other at a speed of
600 km/h. Upon reaching the other train, the fly turns around and continues
towards the first train. How many kilometers does the fly travel before getting
squashed in the collision of the two trains?

2). You have to measure exactly 4 liters of water, but you only have a 3-liter
bottle and a 5-liter bottle. How do you do it?
Sol:-

Method 1:
1. Take 5 lit water and pour it into 3 lit mug.
2. Pour 3 lit mug water outside.
3. Transfer 2 lit water from 5 lit mug to 3 lit mug.
4. Now take 5 lit water and pour 1 lit into 2 lit water.
Then we remain 4 lit water in 5 lit mug.
Method 2:
1. Fill the 3-liter bottle and pour it into the empty 5-liter bottle.
2. Fill the 3-liter bottle again, and pour enough to fill 5-liter bottle. This
leaves exactly1 liter in the 3-liter bottle.
3. Empty the 5-liter bottle; pour the remaining 1 liter from the 3-liter bottle
into the 5-liter bottle.
4. Fill the 3-liter bottle and pour it into the 5-liter bottle. The 5-liter
bottle now has exactly 4 liters.

3). You have 9 balls,equally big,equally heavy-except for one, which is a little
heavier.How would
you identify the heavier ball if you could use a pair of balance scales only
twice?

Sol:- Divide the 9 balls into 3 groups of 3. Compare the weight of two of those
groups. The heavier group should then be obvious, it will either tip the scales,
or, if the scales stay balanced, then it is the group you didn't include.
Now, choose 2 balls from this group and compare their weights, and using the
same logic as before, the heavier ball will be obvious.
4). Some statistics questions regarding correlation and expectation of life time
of a bulb.